Column Stability Factor of a Wood Column

Code:
EXPORT CPWOOD()

BEGIN

// EWS 2015-06-07

LOCAL n1a,n1b,s1,c1,w;

LOCAL l,d,r,fce,cap,sl,mlc;

LOCAL na,nb,n2,s2,c2,c;



// WWPA Timber - 2008 

// 1st is placeholder

// Fc (psi)

n1a:={0,1150,1000,700,1050,

975,925,875,925,800};



// E (psi)

n1b:={0,1.6ᴇ6,1.6ᴇ6,1.3ᴇ6,1.2ᴇ6,

1.3ᴇ6,1.1ᴇ6,1.3ᴇ6,1ᴇ6,1.1ᴇ6};



s1:={"Enter Your Own",

"Douglas Fir Larch (Std)",

"Douglas Fir Larch (#1)",

"Douglas Fir Larch (#2)",

"Douglas Fir South (Std)",

"Hem Fir (Std)",

"Moutain Hemlock (Std)",

"Sitka Spruce (Std)",

"Western Cedar (Std)",

"Western Woods (Std)"

};



// column type

n2:={0.8,0.85,0.9};

s2:={"sawn lumber",

"round poles",

"glued laminated timber"};



// Input

INPUT({l,d,w,{c1,s1}},

"Wood Column - Sawn Lumber",

{"Length (in):","Depth (in):",

"Width (in)","Wood:"},

{"effective (in)",

"effective (in)",

"Douglas Fir"});



// Selection

IF c1>1 THEN

na:=n1a[c1];

nb:=n1b[c1];

ELSE

INPUT({na,nb},

"Lumber Characteristics",

{"Fc* (psi):","E (million psi):"},

{"compression parallel to grain",

"elasticity modulus (in millions)"});

nb:=nb*ALOG(6);

END;



INPUT({{c2,s2}},

"Select Column Type");

c:=n2[c2];



// Calculations

// slenderness

sl:=l/d;

// Fce

fce:=(0.3*nb)/(l/d)^2;

// ratio

r:=fce/na;

// column load capacity

cap:=(1+r)/(2*c)-√((1+r)^2/

(2*c)^2-r/c);

// Maximum Load Capacity

mlc:=na*cap*w*d;



// Output

PRINT();

PRINT("Results:");

PRINT("---------");

PRINT("Slenderness = ");

PRINT(sl);

PRINT("Column Load Capacity =");

PRINT(cap);

PRINT("Column Load Capacity =");

PRINT(mlc+" lb");



RETURN {sl,cap,mlc};



END;